Observation window for furnaces



M. CURRY AND s. H. BARNUM.

OBSERVATION WINDOW FOR FURNACES.

APPHCATION FILED 001127, 1921.

Patented May 30, 1922.

2 SHEETS-SHEET l.

3 wuenfom gw ZI E50)" 0 M. CURRY AND S. H. BARNUM.

OBSERVATION WINDOW\FOR FURNACES. APPLICATION FILED OCT. 27, 1921.

1,%1? 9?6 Patented May 30, 1922.

2 SHEETSSHEET 2.

/ Z095. .22; N 1% x UNITED STATS Para MALCOLM CURRY. or SCARSDALE, NEW YORK, Ann s'mnn a. BARNUM, or HAMIDEN, comnncrrcu'r.

OBSERVATION WINDOW FOR FURNACES.

Application filed October 27, 1921.

To all whom 52 may concern. I

Be it known that we. MALooLM CURRY, a citizen. of the United States, and resident of Scarsdale, in the county of VVeStchester and State of New York. and STARR H. BAR- NUM. a citizen of the United States, and resident of l-lamden, in thecounty of New Haven and State of Connecticut, have invented certain new and useful Improvements in Observation Vindows for Furnaces, of

which the following is a specification.

This invention relates to improvements in observation windows for furnaces, and has for one of its objects to provide windows of simple and inexpensive construction through which the fuel bed may be clearly seen without the observer being subjected to the direct heat and glare of the fire-box and without opening communication between the firebox and the outer atmosphere.

A further object of the invention is to provide simple and efiicient means for prevent ing the transparent glare-eliminating panel of the window from becoming unduly heated and preventing loss of heat during inspection of the fuel bed and influx of the outer atmosphere to the firebox.

To the foregoing and other ends, which will hereinafter appear, the'invention consists in the features of construction, arrangements of parts, and combinations of devices set forth in the following description and particularly pointed out in the appended claims.

In the accompanying drawings, in which the preferred embodiment of the invention is illustrated,

Figure 1 is a front elevation of the win dow applied to the fire-box wall of a furnace;

Fig. 2 a side elevation thereof;

Fig. 3 a transverse section on the line 3-3 of Fig. 1;

Fig. 4: a perspective view of the sliding frame;

Figs. 5 and 6 vertical sectional views on the line 5-5 of Fig. 1, showing the sliding frame in lowered and raised position, respectively; and

Fig. 7 a horizontal section on the line 7-7 of Fig. 1.

The furnace wall 10, which may be of any suitable construction, is provided with a peep-opening 11 at a point suitable for observing the fuel bed. As shown, the peep-- Specification of Letters Patent. Patented 1w ay 30, 1922 Serial No. 510,908.

opening is rectangular in cross section, but it will be obvious that the shape and size of the opening may be varied. and may be formed with flaring sides as shown in the patent to Curry, No. 1,349,562, granted August 17th, 1920. While we prefer to provide the peep-opening in the brick wall of the furnace, as shown, it will be obvious that the opening may be formed in any suitable part of the furnace, and that the window hereinafter described may be attached to furnace walls, casings, or doors of various construction provided with peep-openings Themetallic window frame or casing 12, which is of general rectangular box-like form, is preferably cast in one piece, as shown, said frame being formed with a bolt flange 13 around its open inner end and being held against the outer side of the furnace wall over the peep-opening by bolts 14 and nuts 15. The top, bottom and side edges of the frame are preferably offset from the vertical edges of opening 16, said lugs 17 and 18 forming retaining means for a plate 19 of blue glass or other transparent glareeliminating material. Plate 19 is loosely held against the front face of the frame 12 by the lugs, as shown, to'permit expansion and contraction of the plate, and may be readily inserted and removed for cleaning or renewal by a vertical sliding movement. The top and bottom walls'of the frame 12 are provided with slots or openings 20 adjacent the front wall of the frame to permit free circulation of air past the inner face of the glass plate 19 to assist in keeping said plate cool at all times.

A supplemental metal frame, preferably cast in one-piece, is slidable through the main frame or casing 12. The slidable frame comprises side bars 21 loosely fitting in guideways or channels 22 formed in the imperforate side walls of the frame 12, a top cross-bar 23, a bottom cross-bar 24., and

' top wall of the outer frame or casing 12 is formed with a rectangular slot 27, through which the supplemental frame is slidable, and the bottom wall is formed with an internal recess or channel 28 in which the in termediate cross-bar seats when the parts are in the position shown in Figs. 1, 2, and 5. The bottom wall of the casing 12 is provided with an I-shaped slot 29 to permit movement of the side bars 21 and ,bottom cross-bar 24 therethrough. The to crossbar 23 is provided with a longitudinal slot 30 through which one or more panels or plates- 31 of opaque non-combustible material which is also a non-conductor of heat, such as asbestos boards, are inserted in the upper section of the sliding frame, said asbestos plates 31 resting on bar 25 and being held in the frame by inwardly extending pairs of retaining flanges or ribs 32 formed on the side bars 21 of the frame betweencross-bars 23 and 25. One of the side bars 21 of the sliding frame is provided with a. vertical slot 33, extending between crossbars 24 and 25, through which a sheet or plate 34 of transparent non-combustible or heat-resisting material, such as isinglass, is slidably inserted in the lower half of the frame. The isinglass sheet 34 is retained in the sliding frame by pairs of lugs 35 formed on bars 21, 24 and 25. One side wall of casing 12 is slotted up from its lower edge at 36 to afford clearance for the insertion and removal of the isinglass sheet while the sliding frame is in its lowermost position. A suitable handle 37 has its upper end threaded through a lug 38 depending from the center of cross-bar 24, and a lock nut 39 is pro vided for normally holding the handle against swinging movement. WVhen the window. is packed for shipment, the. sliding frame may be slid partly up so as to register with the flanged casing 12, and the handle 37 may be swung around over the casing after loosening the nut, thus forming a compact package.

It will be observed that when the parts are in the position shown in Figs. 1, 2, 3 and 5 bars 25 and 23 close slots 29 and 27 so that there can be no substantial loss of heat therethrough, while the asbestos boards 31 prevent inward or outward passage of air through the sliding frame and shield the blue" glass plate 19 from heat radiating through the peep-opening 11 and also from flame, hot gases and soot. When the sliding frame is raised by pushing u on handle 37. the asbestos boards are movec out of register with the peep-opening and the sheet of isinglass is moved between the eep-openmg and the blue glass panel to shield the glass anel and permit observation of the fuel bed. %]hen the parts are in raised position it Wlll. be observed that the isinglass sheet and cross-bars 24 and 25 will prevent loss of heat or the influx of cold air through the peepopening, the bar 25 closing slot 27 and bar 24 closing slot 29. The handle 37 engages the bottom wall of casing 12 to arrest the sliding frame in the position shown in Fig. 6-.- It will also be observed that it is impossible to ccidentally leave the sliding frame in raised position as it will drop down when handle 37 is released. In the down position of the sliding frame the isinglass sheet is not exposed to smoke and soot and the glass plate 19 is more effectively protected from the heat of the furnace by the heavy nonheat-conducting asbestos boards. It will also be observed that the sheets or plates 19, 31 and 34 may be readily inserted and removed for renewal or cleaning by a direct sliding movement and that simple means are provided for holding said sheets or plates in place, said means requiring no manipulation.

What we claim is:

1. The combination with a furnace having a peep-opening, of means for supporting a panel of transparent glare-eliminating material outside of the furnace in line with said opening, a support slidable transversely of the line of vision through said transparent panel and opening, and panels of heat-resisting material carried by said slidable support and movable therewith to alternately close the peep-opening, one of said heat-resisting panels being transparent and the other being 105 formed of material which is a non-conductor of heat.

2. The combination with a furnace having a peep-opening, 'of means for supporting a plate of blue glass spaced from the 110 outer end of the peep-opening, a sliding frame held to said supporting means between the furnace and glass plate transversely of the line of vision, and an asbestos plate and a sheet of isingla-ss carried by said 115 frame and movable alternately between the peep-opening and glass plate when said frame is shifted in opposite directions.

3. An observation window for furnaces comprising a casing, a panel of transparent 120 glare-eliminating material extendin transversely of the casing, a'frame slidable transversely'of the casing at one side of the glareeliminating panel, and a panel of heat-nonconducting material and a panel of transmaterial. we

4. An observation window for furnaces comprising a casing, a panel of transparent glare-eliminating material extendin transversely of the casing, a frame slidab e transversely of the casing at one side of the glare eliminating panel, and a panel of heat-nonconducting material and a panel of transparent heat-resisting material carried by the frame and movable therewith to alternately close communication between one end of the casing and the panel of glare-eliminating material, said casing bein provided with openings permitting free circulation of air between the glare-eliminating panel and the panels on the sliding frame.

5. An observation window for furnaces, comprising a casing, a panel of transparentglare-eliminating material extending transversely of the casing, a vertically slidable frame extending transversely of the casing, a panel of heat-non-conducting material held in the upper portion of said frame, and a panel of transparent heat-resisting material held in the lower portion of the frame, said last two panels being? movable with the frame to alternately register with the first panel.

6. An observatlon w1ndow for furnaces, comprising a casing, a panel of transparent glare-eliminating material extending trans-,

versely of the casing, a vertically slidable frame extending transversely of the casing, a panel of heat-non-conducting material held in the upper portion of said frame, a panel of transparent heat-resisting material held in the lower portion of the frame, said last two panels bein movable with the frame to alternately register with the first panel,

. means for limiting the downward movement of the frame, and a handle connected with the frame for shifting the frame upwardly.

7. An observation window for furnaces comprising a panel of transparent glareeliminatin material, means for supporting said pane on a, furnace spaced from the outer side of the furnace, and a shield slidably held to said supporting means to move transversely of the line of vision through the panel of glare-eliminating material, said shield having a transparent portion movable into and out of the line of vision.

8. An observation window for furnaces, comprising a casing adapted for connection at its inner end to a furnace at a eep-opening, a panel of transparent glare-e iminating material extending transversely of the casing, and a panel of heat non-conducting material slidably supported on the casing and shiftable transversely of the casing be tween the inner end of said casing and the panel of glare-eliminating material, said non-conducting panel in one position there of closing communication between the inner end of the casing and the glare-eliminating panel.

9. The combination with a furnace having a peep-opening of a casing attached at one end to the outer side of the furnace at the peep-opening, a panel of transparent glareeliminating material extending transversely of the casing in the line of vision through the peep-opening, and a heat-resisting shield slidable transversely through the casin between the peep-opening and glare-eliminating panel and closing communication between said opening and panel at all times, said shield having a transparent portion movable into and out of the line of vision, and said casing being provided with openings between said shield and panel communicating with the outer air.

10. The combination with a furnace having a peep-opening, of a casing attached at its inner end to the furnace at said opening, a panel of transparent glare-eliminating material extendin transversely of the casing in the line of VlSlOIl through the peep-opening, and a shield slidable transversely of the casing between said panel and opening and closing communication therebetween at all times, said shield having a panel of heatnon-conducting material and a panel of transparent heat-resisting material shiftable alternately between the peep-opening and the glare-eliminating panel, and said casing having openings therein between the shield and glare-eliminating panel communicating with the outer air.

In testimony whereof we hereunto aflix our signatures.

. MALCOLM CURRY.

STARR H. BAR-NUM. 

